... Steel Tubes for low and Medium Pressure Boilers Size: 1/4"-24" Certificate: ISO, API Seamless Steel Tubes for low and Medium Pressure BoilersSpecificationsChina StandardSteel GradeStandardseamless steel ... G3444-1994Seamless steel tubes and pipes forGB ... and Medium Pressure BoilersASTM SA179,SA192, BS3059Seamless Steel TubesGB6479-8610, 20G, Q345, Q390, 10MoVNb, 12CrMo, 15CrMo, 12Cr2MoISO 9329-2-1997 for ...